Chaos Labs researchers found that wash trading “constituted around one-third of trading volume on Polymarket’s presidential market,” while Inca Digital found that a “significant portion of the [trade] volume” on the market “could be attributed to potential wash trading.”

⅓ is too much but ain't the majority 

https://gizmodo.com/new-research-claims-polymarket-is-full-of-wash-trading-2000518668